1. Field of the Invention
This invention relates to microelectronic and optoelectronic packaging. More particularly the present invention relates to an integrated dual thermoelectric cooler and a method of manufacture.
2. Brief Description of the Related Art
A thermoelectric cooler (TEC), or Peltier cooler has been widely used in optoelectronic and microelectronic industries for many years. TEC maintains devices such as laser, CCD, and microprocessor at temperatures at which the devices perform the best. When multiple devices are assembled in one enclosure, especially when optical alignment among the devices is critical, however, packaging design and processing become complicated.
Maintaining a device at its best performing temperature, while being able to vary temperatures of other devices is a key application of the current invention. A thermoelectric cooler functions based upon the Peltier effectxe2x80x94a phenomenon discovered in early 19th century that, accompanying electric current flow through conductors, heat flows in the direction of charge carriers. As depicted in FIG. 1, the electric-flow induced thermal flow is more pronounced in circuits containing DC power supply and dissimilar conductors as shown in FIG. 1. In n-type conductors, electrons are charge carriers flowing from negative pole of DC power supply through conductors A and B to the positive pole. Heat flows from the bottom of conductor B to its top, hence the term heat pump. In p-type conductor, holes are charge carriers; holes and heat flow from the end linked to positive pole of power supply to the end that is connected to the negative pole.
In circuits that contain both n- and p-type conductors in series, electrons and holes flow in opposite directions, as shown in FIG. 2. Heat flows from the bottom to the top in both B and C conductors resulting in constructive heating and cooling effect. When many of these thermal couples are assembled together in series electrically and in parallel thermally; the product, thermoelectric cooler, has enough heating and cooling power for engineering applications.
TECs typically require 3 to 10 V and 1 to 2 A DC power to achieve 60 to 80xc2x0 C. xcex94T cooling. xcex94T, temperature differential between cold and hot side of TE cooler, is a measure of the cooling power of TEC.
Space is at a premium in optoelectronic packaging. As such, what is needed in the art is a TEC that takes up a minimum of space, that can provide multiple controls along its length, and is easily manufactured and maintained.
Thus, what is needed in the art is a multiple-TEC concept that encompasses TEC design, manufacturing, and applications. This concept simplifies multiple-TEC design and manufacturing process; it also enhances optoelectronic device packaging process flexibility. Additionally, the overall component assembly time and cost are reduced, and the quality and reliability of the component assembly is increased.
An object of the invention is to provide a process for thermal control of a plurality of separate components that can be accomplished by a single TEC assembly.
Another object of the present invention is to provide a process for thermal control that minimizes the risk of potential failure.
And yet another object of the present invention is to provide a TEC the configuration of which has a consistent optical centerline.
Another object of the invention is to provide for reduced assembly time, reduced cost, and increased quality and reliability of a TEC.
Other objects, advantages, and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings and the following detailed description, in which like reference numerals refer to like parts and where: